I'm new to software RAID and this list. I read a few months of archives to see if I found answers but only partly... I set up a raid1 set using 2xWD Mybook eSATA discs on a Sil CardBus controller. I was not aware of automount rules and it didn't work, and I want to wipe it all and start again but cannot. I read the thread listed in my subject and it helped me quite a lot but not fully. Perhaps someone would be kind enough to help me the rest of the way. This is what I have done: 1. badblocks -c 10240 -s -w -t random -v /dev/sd[ab] 2. parted /dev/sdX mklabel msdos ##on both drives 3a. parted /dev/sdX mkpart primary 0 500.1GB ##on both drives 3b. parted /dev/sdX set 1 raid on ##on both drives 4. mdadm --create --verbose /dev/md0 --metadata=1.0 --raid-devices=2 --level=raid1 --name=backupArray /dev/sd[ab]1 5. mdadm --examine --scan | tee /etc/mdadm.conf and set 'DEVICES partitions' so that I don't hard code any devide names that may change on reboot. 6. mdadm --assemble --name=mdBackup /dev/md0 ##assemble is run during --create it seems and this was not needed. 7. cryptsetup --verbose --verify-passphrase luksFormat /dev/md0 8. cryptsetup luksOpen /dev/md0 raid500 9. pvcreate /dev/mapper/raid500 10. vgcreate vgbackup /dev/mapper/raid500 11. lvcreate --name lvbackup --size 450G vgbackup ## check PEs first with vgdisplay 12. mkfs.ext3 -j -m 1 -O dir_index,filetype,sparse_super /dev/vgbackup/lvbackup 13. mkdir /mnt/raid500; mount /dev/vgbackup/lvbackup /mnt/raid500" This worked perfectly. Did not test but everything lokked fine and I could use the mount. Thought: lets see if everything comes up at boot (yes, I had edited fstab to mount /dev/vgbackup/lvbackup and set crypttab to start luks on raid500. Reboot failed. Fsck could not check raid device and would not boot. Kernel had not autodetected md0. I now know this is because superblock format 1.0 puts metadata at end of device and therefore kernel cannot autodetect. I started a LiveCD, mounted my root lvm, removed entries from fstab/crypttab and rebooted. Reboot was now OK. Now I tried to wipe the array so I can re-create with 0.9 metadata superblock. I ran dd on sd[ab] for a few hundred megs, which wiped partitions. I removed /etc/mdadm.conf. I then repartitioned and rebooted. I then tried to recreate the array with: mdadm --create --verbose /dev/md0 --raid-devices=2 --level=raid1 /dev/sd[ab]1 but it reports that the devices are already part of an array and do I want to continue?? I say yes and it then immedialtely says "out of sync, resyncing existing array" (not exact words but I suppose you get the idea) I reboot to kill sync and then dd again, repartition, etc ect then reboot. Now when server comes up, fdisk reports (it's the two 500GB discs that are in the array): [root@k2 ~]# fdisk -l Disk /dev/hda: 80.0 GB, 80026361856 bytes 255 heads, 63 sectors/track, 9729 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/hda1 * 1 19 152586 83 Linux /dev/hda2 20 9729 77995575 8e Linux LVM Disk /dev/sda: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 1 60801 488384001 fd Linux raid autodetect Disk /dev/sdb: 320.0 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sdb1 1 38913 312568641 83 Linux Disk /dev/md0: 500.1 GB, 500105150464 bytes 2 heads, 4 sectors/track, 122095984 cylinders Units = cylinders of 8 * 512 = 4096 bytes Disk /dev/md0 doesn't contain a valid partition table Where previously, I had /dev/sdc that was the same as /dev/sda above (ignore the 320GB, that is separate and on boot, they sometimes come up in different order). Now, I cannot write to sda above (500GB disc) with commands: dd, mdadm -zero-superblock etc etc. I can write to md0 with dd but what the heck happened to sdc?? Why did it become /dev/md0?? Now I read the forum thread and ran dd on beginning and end of sda and md0 with /dev/zero using seek to skip first 490GB and deleted /dev/md0 then rebooted and now I see sda but there is no sdc or md0. I cannot see any copy of mdadm.conf in /boot and initramfs-update does not work on CentOS, but I am more used to Debian and do not know the CentOS equivalent. I do know that I have now completely dd'ed the first 10MB and last 2MB of sda and md0 and have deleted (with rm -f) /dev/md0, and now *only* /dev/sda (plus internal had and extra 320GB sdb) shows up in fdisk -l: There is no md0 or sdc. So after all that rambling, my question is: Why did /dev/md0 appear in fdisk -l when it had previously been sda/sdb even after successfully creating my array before reboot? How do I remove the array? Have I now done everything to remove it? I suppose (hope) that if I go to the server and power cycle it and the esata discs, my sdc probably will appear again ( I have not done this yet-no chance today) but why does it not appear after a soft reboot after having dd'd /dev/md0? andrew henry Oracle DBA infra solutions|ao/bas|dba Logica -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
